Supersensitized photographic silver halide emulsions



Patented July 7, 1953 SUPERSENSITEZED PHOTOGRAPHIC SILVER HALIDE EMULSION S Jacob Joseph Jennen, Antwerp, and Oscar Hendrik Vandenbroele, Wilrijk-Antwerp, Belgium, assignors' to Gevaert Photo-Producten N. V., Mortsel-Antwerp, Belgium, a company of Belgium Application August 4, 1947, Serial No. 766,098 In Germany May 22, 1941 Section 1, Public Law 690, August s, 1946 Patent expires May 22, 1961 This invention relates to a process for sensitizing photographic silver halide emulsions by means of dyestuff combinations. In the present case, the expression combination does not mean a chemical combination but an association in a larger sense, i. e., a union in action.

As generally known, the effect of a sensitizer is not in proportion to the quantity added to the emulsion; it passes through a certain maximum by raised concentration.

A combination of sensitizers usually does not produce a larger effect; it often causes but a smaller effect than a single sensitizer when the latter is used in a concentration equal to the sum of the concentrations of the mixed dyestuffs.

It is also known to obtain a high supersensitizing effect from certain sensitizer combinations. Such a supersensitizing effect does not imply an increase of the sensitivity of an emulsion all over the spectrum but anincrease of the sensitizing maximum resulting from the addition of a second or even third chemical compound.

The number of supersensitizing associations is proportionally small in comparison with the number of possible combinations. So it appears from the U. S. Patent No. 2,066,968 that the combination of 1-1-diethyl-seleno-2'-cyanine-iodide with 2-2-diethyl-5-5-tetraethyl diamino-thiocarbocyanine-iodide. produces good panchromatic sensitizing Which is due to the fact that the green gap in thesensitizing curve of the carbocyanine is quite filled by a strong increase of 'the maximum of I the pseudocyanine in the green part which strong increase is effected by the, carbocyanine. In the same sense, an increase of the sensitizing effect of 2'-cyanines and 2-2"-carbocyanines, it is known, can be achieved by addition of other sensitizing dyestuffs.

Known added dyestuffs are mesosubstituted carbocyanines of the following-general formula:

wherein Z is non-metallic atoms required to complete a heterocyclic ring, or thio and seleno-4'- carbocyanines:

4 Claims. (Cl. 95-7) 2 or carbocyanines bases without X and R, or styryls: I

wherein the two CN groups are coupled by a pentamethine chain being partly'closed by a side bridge, or styryl bases.

It is. an object of our invention to provide a new process for the manufacture of photographic silver halide emulsions.

Another object of the present invention isv to provide new photographic silver halide emul- 810115. I

Further objects will appear from the following description.

We have found that the process of sensitization by means of dyestuff combinations can be applied most successfully by using two or more dyestuifs at least one of which corresponds tothe following general formula:

V wherein Z and Y are non-metallic atoms required to completea heterocyclic or an isocyclic ringwhich may have a fused-on arylene group, and n is 1 or 2. r

The hydrogen 'of the open chain may berepla'ced. by hydrocarbon groups, halogen or carboncontaining bridges.

. The compounds totbe usedin accordance with our invention, since being easily soluble, mostly even water-soluble can, fromatechnical point of view, easily b'ehandled, i. "e., withoutthe use of any organic solvents. For this very reason, they are also unstable in photographic baths so that after bathing colorless photographic layers are obtained.

Some examples-of usable supersensitizing dyestuffs according to our invention are given hereinafter:

(1,) 1 phenyl 3- methyl 5 hydroxypyrazolyl alpha methyl trimethine 1 L phenyl 3 methyl 5 pyrazolone p -p di ammonium sulphonate JL,N. il i 3 v (2) 1 phenyl 3 methyl 5 hydroxypyrazo1y1 alpha. beta. butyiene trimethine 1 phenyl 3 methyl 5 pyrazolone p p di ammonium sulphonate CH;C-CCH=C-('J=C-CCH5 5H2 CH1 l N3. HrHa O N N N I i Ca 4 OsN 4 (BBHASOQNHA (3) 5 hydroxy 3 phenylisoxazolyl alpha carbethoxy alpha, methyltrimethine 3 phenylisoxazolone-5 (4) harbituryl-pentamethine-hydroxyuraci1 (5) (1 oxy 3 oxyhydrindyi 2) Ibeta, chlorotrimethine-indandione.

ONa

y tivity of pseudocyanines and alpha-alpha,- carbocyam'nes isincreased. Examples of pseudocyanines areas follows: 7

(6) 3,3-diethy1-2,2'-cya.nine iodide 2H5 Cams (7) 3,1-diethy1-thia. 2-cyanine iodide AME. C2115 I (a) 3,1-diethy1-4,5-benztma- 2 -cyanine' iodide I 02115 C 2H5 means of the :above dyestuffs, the sensiv 4 w (9) 3,1 diethyi- .cyanine iodide.

The following are examples of usable 2,2'-ca.rbocyanines:

(10) 3,3 9 triethyl 6,7,6,7 dibenzoxocarbocyanine iodide 02115 (11) 9 methyl 3,3 diethyl 4,5,435 di- (E 2H5 V I benzthiacarbocyanine iodide N I $2115 I (14) 33' dimethyl 9 anine iodide.

- ethyl thiacarbocy- The specification is accompanied by drawings in which the supersensitizing effects of our new associations are shown;

In Fig. 1, the curve A represents the sensitivity o of an emulsion containing 3,3'diethy1-2,2'- -cya.-

nine iodide.

The curve B represents the sensi? tivity of the same emulsion containing l-phenyl- 3 methyl 5 hydroxypyrazolyl alphamethyl 7 trimethine 1 phenyl 3 methyl 5- pyrazolone p p di-ammonium sulphonate.

' The curve C represents the sensitivity 'of the same emulsion containing 3,3 -'diethy1- 2,2 -cyanine 4 phenyl thiazo lo 2 iodide, and. l .p henyl 3 methyl 5 -hydroxypyraz'olyl {alpha' methyl trimethine' 1- phenyl 3"'-' methyl 5 pyrazolonep p diammonium sulphonate.

In Fig. 2, the curve D represents the sensitivity of an emulsion containing 3 ,3-diethy1-2, 2 -cyanine iodide. The curve E re resents the sensitivity of the same emulsion containing l-phenyl- 3 methyl 5 hydroxypyrazolyl alpha betabutylenetrimethine 1 phenyl 3 methyl 5- pyrazolone p p di ammonium sulphonate. The curve F represents the sensitivity of an emulsion containing 3,3-diethyl-2,2-cyanine iodide and 1 phenyl 3 methyl 5 hydroxypyrazolyl alpha beta butylenetrimethine 1- phenyl 3 methyl 5 pyrazolone pp diammonium sulphonate.

In Fig. 3, the curve G represents the sensitivity of an emulsion containing 3,3-9-triethyl-6,7,- 6,7'-dibenzoxocarbocyanine iodide. The curve H represents the sensitivity of the same emulsion containing 1 phenyl 3 methyl 5 hydroxypyrazolyl alpha methyl trimethine 1- phenyl 3 methyl 5 pyrazolone pp diammonium sulphonate. The curve I represents the sensitivity of the same emulsion containing 3,3 9 triethyl 6,7,6)? dibenzoxocarboc'yanine iodide and lphenyl-3-methy1-5-hydroxypyrazolyl alpha methyl trimethine lphenyl 3 methy1 5 pyrazolone p p diammonium. sulphonate.

In Fig. 4, the curve J represents the sensitivity of an emulsion containing 3,3 9 triethyl 6,7,- 6',7'-dibenzoxocarbocyanine iodide. The curve K represents the sensitivity of the same emulsion containing 1 phenyl 3 methyl 5 hydroxypyrazolyl alpha beta butylenetrimethine- 1 phenyl 3 methyl 5 pyraz'olone p pdi-ammonium sulphonate. The curve L represents the sensitivity of the same emulsion containing 3,3 9 triethyl 6,7,6',7 dibenzoxocarbocyanine iodide and l-phenyl-3-methyl-5- hydroxypyrazolyl alpha beta butylenetrimethine 1 phenyl 3 methyl 5 pyrazolonep-p-di-ammonium sulphonate.

This invention may be applied to ordinary silver halide gelatine emulsions. However, the dyestuiT combinations of our invention-may also be used in emulsions wherein instead of gelatine another binder is employed, as, e. g., resinous substances or cellulose derivatives, this without a noxious influence upon the light-sensitive substance.

As far as the supersensitizing dyestuffs are concerned, the dyestuff listed as Example 2 is mentioned in the British Patents Nos. 414,664 and 506,998. 2 (3 hydroxythionapthenyl 2- allylene) 3 oxo 2 3 dihydrothionaphthene is mentioned in Chemisches Zentralblatt 1940, II 1577.

The dyestufi" of Example 2 the preparation of which has not been described yet may be obtained by condensation of phenylmethylpyrazolone-pammonium sulphonate with sodium-oxymethylene-cyclohexanone in methyl alcohol as disclosed in the co-pending application Serial No. 766,097, filed August 4, 1947. The dyestuif 5-hydroxy-3- phenylisoxazolyl alpha carbethoxy alphamethyltrimethine-3-phenylisoxazolone-5 may be prepared as follows: 0.02 mol phenylisoxazolone, 0.01 mol sodium acetyl pyruvic acid ethyl ester and 60 cm. methyl alcohol are heated on the water bath for two hours whereafter the intensive-violet colored mixture is poured into 400 cm.

of a 20 per cent potassium bromide solution. The

precipitated dyestufi is-then drained. Thedyestufif obtained is probably of the formula given inExample3. I w J The dyestuif barbituryl pentamethine hydroxyuracil prepared in the following way: 0.04 molbarbituric' acid, 0.02 mol glutacondialdehydes dian'ilido hydrobromide and 0.04 -.mol triethylamine are mixed in 60 cm. of alcoholwhereupon the mixture is heated on the-water bath-for thirty minutesand then-cooled. Next the. dyestufi is drained and recrystallized from water. The absorption maximum of this violet dyestuff, which is probably the dyestuif of Example 4, lies at about 592 my" V The dyestufi (l-oxo-B-oxyhydrindyl- -Z)-betachlorotrimethine-indandione is prepared as follows: 0.02 mol indandione, 0.04 mol chloromalondialdehyde dianilhydrochloride and 0.02 mol sodium hydroxide are mixed in 250 cm. methylalcohol and allowed to remain for two days. the formed crystals are drained and washed with ether. The dyestuif obtained is probably that of- Example 5. I V

The preparation of the pseudo and carbocyanines to be used according to our invention is suificiently known from the respective literature.

In order to carry out our invention, the dyestufis may be mixed with the emulsion either ins dividually or in combinations.

It is believed that the general method and the specific examples of our invention, as well as the advantages thereof, will be apparent from the foregoing detailed description. It will also be apparent that while we have shown and described preferred examples of our invention, changes may be made without departing from the spirit of the invention, as sought to be defined in the following claims.

We claim:

1. Photographic silver halide emulsion having incorporated therein a supersensitizing dyestuff composition comprising at least one sensitizing dyestufi and at least one polymethine dyestufi, said sensitizing dyestufi being selected from the group consisting of 3,3 diethyl 2,2 cyanine iodide and 3,3,9-triethyl-6,7,6',7-dibenzoxocarbocyanine iodide, said polymethine dyestufi having the following general formula:

cyanine iodide and 1 phenyl 3 --methyl- 5- hydroxypyrazolyl alpha methyl trimethinel phenyl 3 methyl 5- pyrazolone p pdi-ammonium sulphonate.

3. A photographic silver halide emulsion having incorporated therein a supersensiti zing dye stuff composition comprising 3,3 diethyl 2,2-

cyanine iodide and 1 phenyl 3 methyl 5- hydroxypyrazolyl alpha beta butylene trimethine 1 phenyl 3 methyl 5 pyrazolone- Then U 1 .111-di=ammoniumulpb9n tex, 5;: :1 14.. A. DhOB gmDD j IV I. ha id emul ion. hai

ingaincomorat dii er in a up rs nsitizin dye:

' stufi composition comprising 3,3 :Q;;tri9thy1;

6,7,637'edibenzoxoparbocyanine iodide and 1- 5 phenyl 3 -'methyl 5 hydroxypyrazolyl a1- pha'y: ,methyl trimethine 1 phenyl 3- methyl- 5 pyrazolonep p d1 ammonium sulphonate. V

'JAQOB JOSEPH JENNEN. V V T OSCAR HENDRIK VANDENBROELE.

Refgroncs Cited in tho file of this patent UNITED STATES PATENTS Number Name Date M'ees Aug. 16, 1938 Schwarc Nov. 5, 1940 Gaspar Mar. 3, 1942 

1. PHOTOGRAPHIC SILVER HALIDE EMULSION HAVING INCORPORATED THEREIN A SUPERSENSITIZING DYESTUFF COMPOSITION COMPRISING AT LEAST ONE SENSITIZING DYESTUFF AND AT LEAST ONE POLYMETHINE DYESTUFF, SAID SENSITIZING DYESTUFF BEING SELECTED FROM THE GROUP CONSISTING OF 3,3'' - DIETHYL - 2,2'' - CYANINE IODINE AND 3,3'',9-TRIETHYL-6,7,6'',7''-DIBENZOXOCARBOCYANINE IODIDE, SAID POLYMETHINE DYESTUFF HAVING THE FOLLOWING GENERAL FORMULA: 